Warehouses, manufacturing facilities, and large retail outlets typically include one or more loading docks for transferring goods to and from trucks, trailers, and other shipping vehicles. Conventional loading docks usually consist of an opening in an exterior wall of the building. The opening is typically positioned a few feet above the ground so that it is approximately level with the bed of shipping vehicle, and is usually covered by a sectional door.
Some loading docks include a dock leveler with a movable deck or ramp to adjust for any misalignment between the floor of the loading dock and the bed of the trailer. Vertical dock levelers are, as the name implies, stored in a generally vertical position when not in use, while horizontal dock levelers are stored in a lowered and generally horizontal position. With either type of leveler, the aft edge of the ramp is typically attached to a hinge structure mounted to the floor of the loading dock or to the rear wall of a deck pit formed in the floor. The forward edge of the ramp typically carries a pivoting lip extends outwardly to engage the trailer bed for use.
To transfer goods to or from a trailer, the rear doors on the trailer are opened and the trailer is backed up to the loading dock opening. With the trailer in position and the loading dock door raised, horizontally stored decks first pivot upwardly about the rear hinge to allow the lip to extend, and then downwardly toward the open end of the trailer until the lip comes to rest on the bed. Vertically stored decks simply rotate downwardly about the rear hinge as the lip extends outwardly and ultimately comes to rest on the trailer bed. Workers, fork lifts, etc. can then move into and out of the trailer to load and/or unload cargo. As cargo is moved into or out of the trailer, the dock leveler moves up or down as needed to accommodate any vertical movement of the trailer bed relative to the building floor. Various types of dock levelers and associated features are disclosed in, for example, U.S. Pat. Nos. 5,475,888, 6,125,491 and 7,216,392, each of which is incorporated herein in its entirety by reference.
Gaps can form around the top and sides of the trailer and the loading dock opening when the trailer is in position and the loading dock door is open. These gaps can allow conditioned air to exit the building or the trailer, and/or allow undesirable elements (e.g., rain, snow, warm/cold outside air, debris, insects, etc.) to enter the building or the trailer, resulting in energy losses, undesirable working conditions, spoiled goods, and/or other deleterious effects. For this reason, many loading docks include a compressible dock seal or a shelter that extends around the top and sides of the loading dock opening to seal gaps that may exist between the aft end of the trailer and the dock opening. Examples of such sealing structures are disclosed in, for example, U.S. patent application Ser. No. 11/860,468, filed Sep. 24, 2007, and entitled “LOADING DOCK TRUCK SHELTERS,” U.S. patent application Ser. No. 12/360,082, filed Jan. 26, 2009, and entitled “LOADING DOCK TRUCK AND TRAILER SEALS AND ASSOCIATED SYSTEMS AND METHODS,” and U.S. patent application Ser. No. 12/334,167, filed Dec. 12, 2008, and entitled “SEGMENTED DOCK SEALS FOR TRUCK LOADING DOCKS AND ASSOCIATED SYSTEMS AND METHODS,” each of which is incorporated herein in its entirety by reference.
Undesirable leak paths can also exist beneath and around deployed dock levelers. Gaps may exist, for example, between the sides of the deck lip and the trailer bumpers positioned on opposite sides of the loading dock opening. The area under the front of both horizontally stored and deployed decks can also create leak paths. Such leak paths can allow outside air and debris to flow under the front of the deck and pass upwardly into the building through gaps between the rear and side edges of the deck and the adjacent pit walls. Various types of seals have been used around and beneath the deck to seal these leak paths. Such seals are disclosed in, for example, U.S. Pat. Nos. 8,046,857 and 7,594,290, each of which is incorporated herein in its entirety by reference.